The initial impulse distribution of a transformer winding grounded at one end is given by the well known relation V=V.sub.0 sinh a (1-X)/sinh a, where X=percent distance along the winding from the line end, a=(C.sub.g /C.sub.s).sup.1/2 where C.sub.g =the total capacitance between the winding and ground and C.sub.s =the total series capacitance of the winding.
The initial impulse distribution along the winding provides a voltage stress at the impulsed end of the coil greater than the stress caused by the steady state voltage distribution within the winding. The ratio of the impulse voltage stress to the operating voltage stress is equal to a. The impulse (initial) stress can be reduced by increasing C.sub.s causing a to decrease. The effective series capacitance in a disc wound transformer winding is composed of the turn-to-turn capacitance between the electrical conductors making up the winding and the section-to-section capacitance between the sections along the disc winding. Various attempts have been employed to increase the effect of both the turn-to-turn and section-to-section capacitance of the winding upon the effective series capacitance of a disk winding section. One method for increasing the use of the turn to turn capacitance consists in the employment of electrostatic shields between the turn conductors. U.S. Pat. Nos. 3,691,494 and 4,042,900 teach various configurations of inter section electrostatic shields for increasing the series capacitance in disk windings. The aforementioned U.S. patents teach the insertion of shields in disk winding arrangements that are continuously connected in mechanical and electrical series. A second method of configuring disk winding sections makes more effective use of the section-to-section capacitance is taught in French Pat. No. 1,147,282. This patent shows that an increase in series capacitance can be achieved by connecting the sections nonsequentially. A third method which maximizes the use of the turn-to-turn series capacitance in the winding is to interlace the turns so that the electrically sequential turns are not physically adjacent.
The purpose of this invention is to provide an electrostatic shielding arrangement for nonsequential disk windings wherein the effective series capacitance of the winding is the highest heretofore obtained in a disk winding configuration.